Biguanide azo dyes



2,898,332 VBIGUANIDE AZO DYES No Drawing. Application November 21, 1957 Serial No. 697,765

9 Claims. (Cl. 260-148) The present invention refers to a new series of dyestufis of the formula:

in which R and R represent radicals ofazo dyes, which radicals are not necessarily identical. These new dyestufis, which lend themselves to excellent all-round application, possess good fastness characteristics and cover wide range of attractive shades.

These products'can be prepared via the reaction of dicyanamide with aromatic amines, as follows:

The intermediate substituted cyanoguanidine can then be reacted with a second mol of the same or a different amine, as follows:

i a RNH-C-N-CEN RNHz RNH(||3-N-(|3NHR' NH NH bit! .It has been discovered that these reactions succeed not only with simple amines, such as m-aminophenol, but also proceed smoothly with aminosulfonic acids such as I-acid and with certain azo dyes containing free amino groups. Furthermore, the products thus obtained are capable of diazotization and coupling reactions, depending upon the substituents present, and thus can give rise to a great variety of novel azo dyes, characterized by the presence of the biguanide linkage,

NH IHIH l as abridge between similar or dissimilar moieties of th molecule. This linkage is very stable and is not affected by the ordinary procedures of preparing and applying azo dyes. For example, if hydroxyl groups are'present in positions ortho to the azo linkages, the dyes maybe converted by ordinary methods to metallic complexes either on the fiber or in bulk. *On the other hand, the use of proper hydrolytic conditions may lead tothe corresponding guanylureas or biurets,

and

.nNntli Nnqlz -Nnn' The varied components which can be incorporated into the novel dyes of the present invention give rise to a wide variety'of shades and other properties, which can be altered'according to the purpose in view. Thus,it is possible to obtain either azo pigments, which may also be of use for the dyeing of acetate or other synthetic fibers, or water-soluble azo dyes, which may be useful States Patent for the dyeing of wool, silk, cotton, nylon, etc. Because the biguanide nucleus is basic in character, even the unsulfonated azo pigments may be applied as basic dyes.

Probably the largest and most valuable single group are the direct dyes for cotton. An especially valuable series are derived from J-acid and have the formula:

-SO3H NH NH in which Ar and Ar are aromatic radicals.

Probably the most useful method of preparation for compounds of this type is that in which J-acid is first reacted with dicyanamide to give 1,5-bis(S-hydroxy-7- sulfo-2-naphthyl)biguanide. This intermediate can then be reacted with a wide variety of diazotized aromatic amines to give the desired bis-azo and polyazo dyes. By carrying out the coupling in a step-wise manner and using two difierent diazo components, unsymmetrical dyes can be readily obtained.

Alternatively, one mol of J-acid can be reacted with 0 1! mol of dicyanamide to give N-(5-hydroxy-7-sulfo-2- naphthyl)-N-cyanoquanidine. This intermediate can be .coupled' with one mol of a diazo component and then reacted with one mol of J-acid to give the biguanide which can be further coupled with any desired diazonium salt. In this way, the preparation of pure unsymmetrical azo dyes is facilitated. This case of preparation of pure unsymmetrical azo compounds is in marked contrast to the corresponding urea dyes. The only practical method .of preparation of the urea dyes is by reaction of phosgcne with a mixture of aminoazo compounds and, even under carefully controlled conditions, this leads to a mixture of products.

If a symmetrical dye is desired, a useful alternative is to couple the diazonium salt first with an arninonaphthol such as J-acid and then to react two mols of this dye with 'one mol of dicyanamide.

Obviously, other aminohydroxy compounds may beused; -Examples of such are 1-amino-7-naphthol, 1- amino-S-naphthol, 2-amino-6-naphthol, ortho-, meta-, and para-aminophenols, l-amino 8 hydroxynaphthalene-3,6-

disulfonic acid, Z-amino-8-hydroxynaphthalene-6-sulfonic,

' thalene-7-sulfonic acid, and 2-arnino-8-hydroxynaphthalene3,6-disulfonic acid.

Examples of useful diazo compounds are those derived from aniline and substituted anilines, alphaand betanaphthylamine and derivatives, aminoazobenzene, aminoazobenzene sulfonic acid, as well as more complicated aminoazo compounds, such as H-acid coupled to cresidine. Of particular use are diazo components containing metallizable groups ortho to the diazo group, since when these are used with biguanide derivatives which couple ortho ,to an hydroxyl group, metallizable dyes are obtained.- Ex: amples of such diazo components are 2-arninoanisolea4 sulfonic acid, 2-arninophenol-4-sulfonic acid, 2-amin0-4- chlorophenol, 2-amino-4-chlorophenol-6-sulfonic acid, 2- amino-4-nitrophenol, 2-amino-4-nitrophenol 6 sulfonic acid, anthranilic acid, l-amino-2-naphthol-4-sulfonic acid, etc. i

The metals usually used to form the 'metallized dyes are those of atomic numbers 24-30, namely chromium, manganese, iron, cobalt, nickel, copper and zinc. These are usually used in the form of their salts. Other polyvalent metals such as those of the various transition series-in the periodic table (atomic numbers 42-47, 58-71, and 74-' 80), as well as aluminum, lead, zirconium, and the like similarly can be used.

In general, any diazotizable amine can be used (in the form of its diazo) to couple with thehydroxyaryl biguanides to form the new dyes of our invention. The more important ones are to be found describedin- The Chemistry of Synthetic Dyes by Venkataraman, Academic Press, New York, 1952, in the various chapters on azo dyes and intermediates, such as chapters 3-6 inclusive, 8- 22 inclusive.

These methods of preparation, all based on dicyanamide, are considered the most desirable, but the invention is not limited in any Way by preparative methods. A number of methods are known for the preparation of N- arylcyanoguanidines, the intermediates obtained in the above syntheses. For example, cyanogen chloride may be reacted with guanidine, or a derivative of guanidine; however, cyanogen chloride is toxic and difiicult to handle, and the preparation of a suitable guanidine by this method involves. additional problems.

This application is a continuation-in-part of our copending application, Serial No. 462,373, filed October 14, 1954,

now abandoned, which is a division of our copending application, Serial No. 358,574, filed May 29, 1953, now

abandoned.

The present invention is further described in the following examples. Parts are by weight, unless otherwise specified.

Example 1 Example 2 H COHPN=N The diazo is prepared in the ordinary way from 9.6

'parts of aniline and gradually added to a solution of 32.8

parts of the product of the preceding example and 53.0 parts of sodium carbonate in. 250 parts of water. The mixture is then finally allowed to stir overnight and filtered. The product is washed with brine and dried.

Example 3 Example 4 Nn-c-NH-c--NH 0,3

Hols 0,1:

Dianisidine tetrazo is prepared from 1.22 parts of dianisidine in the ordinary way. The tetrazo solution is neutralized with sodium bicarbonate. To this treated solution, a solution of 1.78 parts of R-salt and 0.27 part of sodium carbonate in 51 parts of water is added slowly in one hour. The resulting slurry is treated with 18 parts of pyridine and then a solution of 3.54 parts of the product of the preceding example, and 0.2 part of sodium hydroxide and 20 parts of water. The mixture is finally allowed to stir overnight, and heated to 50 C. for a few hours and filtered. The product is washed with. brine. and. dried. The product dyes cotton reddish.- blue.

Example 5 OH H with sodium carbonate, and salted with parts of sodium chloride. The mixture is cooled thoroughly and filtered, the product being washed with salt solution followed by alcohol.

Example 6 soar: 0311 A solution of 8.6 parts of 4-aminoazobenzene-3,4'-disulfonic acid in 100 parts of water is iced to 15 C. and diazotized in the ordinary way with hydrochloric acid and sodium nitrite. The resulting diazo is added to a H03S SOSH solution of 5.86 parts of the 'bis-J-acid biguanide of [1 Example 5 in 200 parts of water. There is finally added =N C0Hi a solution of 8.4 parts of sodium bicarbonate in 150 Example 9 parts of water. The reaction mixture is then stirred 0H overnight, and treated with 35 parts of sodium hydroxide and 240 parts of sodium chloride. The product is filtered and washed thoroughly with alkaline salt solution. It may be purified by reprecipitation from aqueous solution with alkali and salt. The product is a direct brilliant The diazo is prepared in the ordinary way from 1.86 parts of aniline with dilute hydrochloric acid and sodium nitrite solution. This .is added to a solution of 5.89 parts of bis-J-acid biguanide of Example 5 in dilute red aqueous sodium carbonate. The mixture is stirred over- 7 night, and the scarlet precipitate filtered and dried at Exampl 2 we 75 C. It dyes cotton cloth yellowish-scarlet shades.

1103's H033 NHONHCNH -s0 H SO H lie l1; QN=N N=N The diazo prepared in the ordinary way from 4.47 Example 10 parts of 2-aminoanisole-4-sulfonic acid is added at 5-10" C. to a solution of 5.86 parts of the bis-J-acid H0 OH biguanide of Example 5 and 10.6 parts of sodium carl v I bonate in 200 parts of water. The resulting mixture is stirred overnight and filtered. The product is washed O E E O with salt solution and dried. It is then copperized in l IH NH the ordinary way with ammoniacal copper sulfate solu- 1 tion. It gives reddish-purple dyeings having excellent light fasmess A mixture of 48.0 parts of m -aminophenol, 17.8 parts of sodium dicyanamide, and 200 parts of water is heated rapidly to 90 (3,, followed by the gradual addition of 92 Example 8 parts of 5 N hydrochloric acid. The'mixture is then he .YI iH N=NON=N a a refluxed for several hours, treated with 28 parts of an- 5.82 parts (pure basis) of 4-aminoazobenzene-4'-sulfonic hydrous sodium sulfate, and allowed to stand overnight. acid with hydrochloric acid and sodium nitrite; This is The dark lower layer is removed, dissolved in dilute hythen added to a solution of 5.86 parts of the bisJ-acid drochloric acid, and reprecipitated with sulfuric acid. biguanide of Example Sand 8.4 parts of sodium bicar- 'I heproduct, in the form of the acid sulfate, is filtered, bonate in 200 parts of water. The mixture is stirred washed, and dried. A good yield is obtained. It may overnight, salted with 70 parts of sodium chloride, and i be purified by dissolving in sodium hydroxide solution filtered. The product may be purified by resalting. It and precipitating with sulfuric acid. It melts with degives direct bluish-red dyeings on cotton. composition at approximately 227 C.

The diazo is prepared in the ordinary way from 7 t. Example 11 SO H A solution is prepared from 3.83 parts of the bis- (m-hydroxyphenyl)biguanide of the preceding example with 100 parts of water and just enough sodium hydroxide to efiect solution. To this is added 47 parts of sodium carbonate solution followed by cooling to 20 C. There is then slowly added the diazo solution prepared in the usual way from 6.05 parts (pure basis) of amino G-acid, 100 parts of water, 13 parts of 5 N hydrochloric acid, and approximately 20 parts of N/l-sodium nitrite solution. The reaction mixture is stirred overnight, salted with 35 parts of sodium chloride, and filtered. The product is dried at 75 C. It is a yellow dye. It is probable that other isomers are present in addition to the one represented by the above formula.

Example 12 HO OH I NH I HH HO S -SO3H in which Y and Y are aromatic carbocyclic radicals of less than three six-membered rings, at least one of Y and Y being substituted by a hydroxyl group, there being in the said hydroxy substituted radical on the same ring as the hydroxyl group an unsubstituted position capable of coupling and (b) metal complexes of the azo dyes of (a) derived from a polyvalent metal selected from the group consisting of metals of atomic number 24-30 inclusive, 42-47 inclusive, 58-71 inclusive, 74-80 inclusive, aluminum, lead and zirconium.

2. A20 dyes obtained by coupling diazonium salts with compounds having the formula:

11(1) 0H os0...N NH C NH O NHON.N NO. t t H H The diazo prepared in the ordinary way from 2.76 parts of p-nitroaniline is added at 15 C. to a solution of 3.83 parts of bis-(m-hydroxyphenyl)biguanide of Example 10, 0.16 part of sodium hydroxide and 8.2 parts of sodium acetate in 100 parts of water. The resulting mixture is stirred overnight and then filtered. The product is washed with water and dried. It is slightly soluble in water in the presence of acetic acid or hydrochloric acid. It dyes some synthetic fibers such as acetate rayon and polyacrylonitrile fiber yellow. It is probable that other isomers are present in addition to the one represented by the above formula.

We claim:

1. Compounds selected from the group consisting of (a) azo dyes obtained by coupling diazonium salts with compounds having the formula:

, O Cu in which Y and Y are aromatic carbocyclic radicals of less than three six-membered rings, at least one of Y and Y being substituted by a hydroxyl group, there being in the said hydroxy substituted radical on the same ring as the hydroxyl group an unsubstituted position capable of coupling.

3. A20 dyes of claim 2 in which the said hydroxyl group is adjacent to the position of coupling.

4. Polyvalent metal complexes of the dyes of claim 3 in which the metal is selected from the group consisting of metals of atomic numbers 24-30 inclusive, 42-47 inclusive, 58-71 inclusive, 74-80 inclusive, aluminum, lead and zirconium.

5. A compound having the formula:

6. A compound having the formula:

7. A compound having the formula:

, 8. A compound having the formula:

0H 0H 1 Q Q 9. A compound having the formula:

E035 NHc=NH-o-NH- 0,11 0011, con,

1% 1m N=N N= N= 0 n H H 0,11

Refrences Cited in the file of this patent UNITED STATES PATENTS 2,455,897 Nagy Dec. 7, 1948 

1. COMPOUNDS SELECTED FROM THE GROUP CONSISTING OF (A) AZO DYES OBTAINED BY COUPLING DIAZONIUM SALTS WITH COMPOUNDS HAVING THE FORMULA: 